Cartridge for applying medicament to an eye from a dispenser

ABSTRACT

A cartridge for actuating a piston-like or accordion-like dispenser-vial for applying medicament to an eye. The cartridge includes a housing for holding the dispenser-vial and a telescoping cylinder for compressing the dispenser-vial in the longitudinal direction to actuate the vial. The cartridge includes a locking mechanism for locking the telescoping cylinder to restrict its movement and a trigger mechanism for releasing the cylinder from the locked position so that a drop is released from the dispenser. The housing includes a finger for engaging the lower eyelid and exposing the conjunctival cul de sac.

This application is a reissue application of U.S. Pat. No. 5,267,986issuing from application Ser. No. 07/863,943, filed Apr. 6, 1992.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a cartridge for applying medicament to an eyefrom a vial-dispenser of the type which is actuated by compression ofthe vial between its nozzle and its bottom wall.

2. Description of Related Art

There are various dispensers which are known for applying medicament toan eye. A typical eye-drop container includes a flexible vial storageportion and a nozzle for dispensing drops of medicament into the eye bysqueezing the vial between its side walls. Less common, but moreprecise, are accordion-like or piston-like dispensers which are actuatedby squeezing the vial between a bottom wall and the nozzle so as tocompress the vial in its longitudinal direction, rather than from itssides. It is these accordion-like or piston-like dispensers with whichthe cartridge of the present invention is particularly adapted for use.An example of a new and improved piston-like dispenser is the subject ofmy co-pending U.S. application Ser. No. 07/801,243 which is incorporatedherein by reference.

Most people encounter difficulty in applying drops to their eyes. Theeye is a very sensitive body part and individuals find it difficult tocontrol reflexive blinking when applying drops thereto. Also, eye dropusers often have poor vision. Poor vision makes it difficult to positionthe tip of the dropper bottle over the eye and frequently causes dropsto be incorrectly applied to the nose or cheek. Additionally, elderlypeople often have difficulty holding a dropper bottle steady orencounter difficulty in squeezing the bottle to apply a proper quantityof the medicament.

Even if the liquid medicament is properly applied to the eye, themedicament's effectiveness is limited. The minimum volume of a drop ofliquid medicament which can ordinarily be introduced into contact withan eye at one time is about 30 μl. Any amount which is greater thanabout 25 μl usually spills over the eyelid onto the cheek since this isthe maximum volume which the eye can ordinarily handle. When eye dropsare applied to the surface of the eyeball, blinking and natural tearflow combine to limit the time to a few minutes that liquid medicamentwill remain effective.

On the other hand, if medicament is applied to the cul de sac of theconjunctiva, the medicament will remain effective for a longer period oftime, maximizing the benefits of applying drops of liquid medicament tothe eye. This is because the conjunctiva is an area of low sensitivityand low tear turnover such that blinking and tearing are avoided.However, because of the difficulty encountered in steadying the dropperand accurately positioning it over the conjunctiva, maximizing theeffectiveness of the medicament remains elusive.

U.S. Pat. No. 4,543,096 describes and illustrates an apparatus havingfinger-like projections which are attached to the front of an eye dropbottle to spread the eyelids apart during the eye drop dispensingprocess. One moveable finger is connected to a lever for both depressingthe lever and simultaneously causing the eyelids to spread apart whileforcing a drop from the dropper bottle. However, the apparatus describedin U.S. Pat. No. 4,543,096 cannot be used with the accordion-like orpiston-like dispensers which are actuated by compression in thelongitudinal direction rather than from the sides. Furthermore, thisapparatus will not properly expose the cul de sac.

Similarly, U.S. Pat. No. 4,531,944 depicts an apparatus for steadyingthe tip of a dropper over the eye and further includes a sighting holeto distract the eye. However, this apparatus does not have a means toexpose the cul de sac nor keep the lower eyelid depressed.

Typical eye-drop dispensers also have the disadvantage that the forcewhich is necessary to actuate the dispenser to emit a drop is not in thesame direction as the motion which is necessary to lower the lowereyelid and expose the cul de sac. It would be desirable to have a devicewhich actuates the dispenser with a motion which is in the samedirection as that which is necessary to lower the lower eyelid.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a device which canaccurately deliver a small drop of medicament to the conjunctival cul desac of an eye.

It is a further object of the invention to provide such a device whichcan be used to actuate an accordion-like or piston-like vial-dispenserusing minimal force.

It is a further object of the invention to provide such a device whereinthe motion used to actuate the dispenser to emit a drop is in the samedirection as the motion which is necessary to depress the lower eyelidand expose the conjunctival cul de sac.

It is a further object of the invention to provide a device having thesefeatures which has a simple construction and which is easy tomanufacture.

The foregoing objects are achieved by the present invention whichprovides a cartridge which is particularly adapted for actuating anaccordion-like or piston-like dispenser-vial. The cartridge includes agenerally cylindrical housing which is adapted to receive adispenser-vial between an anterior wall of the housing and a telescopingcylinder. The anterior wall of the housing has an aperture for allowingthe nozzle of the vial to project therefrom. The anterior of the housingis curved with a highly polished and smooth external surface to preventany corneal injury in the event of accidental contact with the eye.

The back of the housing is open and slidably receives the telescopinginner cylinder. When the inner cylinder is pushed toward the anterior ofthe housing it forces the dispenser-vial to compress in the longitudinaldirection between the anterior wall of the housing and the cylinder. Inthe case of some dispensers which can be used with the invention,compression causes a drop of liquid medicament to enter the drop cavityof the dispenser thereby “loading” the drop cavity.

The top of the inner surface of the housing is formed with a notch. Thefront of the telescoping inner cylinder is formed with a rearwardly andoutwardly projecting extension which easily slides past an inclined sideof the notch as the cylinder is pushed into the housing to load the dropcavity of the vial. However, the opposite side of the notch is angled toprevent the cylinder extension from sliding past the notch in theopposite direction, thereby locking the cylinder so that the vial is inits loaded position.

The housing is formed with a trigger mechanism for unlocking thecylinder. A trigger button is disposed on the top of the housing.Depression of the trigger button forces the extension of the innercylinder away from the notch allowing the cylinder to move past it. Thecompressed dispenser-vial forces the inner cylinder rearward. Uponexpansion of the dispenser-vial a drop is emitted through the dispensernozzle.

The bottom of the anterior section of the housing is formed with a softfinger which is adapted to engage the lower eyelid. In order to apply adrop, the inner cylinder is pushed into its locked position to load thedispenser-vial. The nozzle projecting from the cartridge is thenpositioned over the eyeball with the finger pressing on the lower eyelidto expose the conjunctival cul de sac. When the trigger is depressed theresulting motion of the cartridge will be in the sam direction as themotion which causes the finger to lower the lower eyelid and expose theconjunctival cul de sac as a drop is emitted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a cartridge in accordance with theinvention.

FIG. 2 is a detailed cross-sectional side view of a cartridge inaccordance with the invention containing a dispenser-vial.

FIG. 3 is an isolated detailed view of the trigger mechanism of thecartridge of the invention.

FIG. 4 is a view of the cartridge from the anterior.

FIG. 5 is a cross-sectional view of a dispenser-vial which can be housedin and actuated by the cartridge of the invention, wherein thedispenser-vial is illustrated in the expanded position.

FIG. 6 is the view of FIG. 5, except the dispenser-vial is illustratedin the compressed position.

DETAILED DESCRIPTION OF THE INVENTION

The cartridge of the invention is specially adapted to work inconjunction with an accordion-like or piston-like dispenser-vial. Anexample of a new and improved piston-like dispenser which can be used inthe cartridge of the invention is the subject of my co-pendingapplication Ser. No. 07/801,243 which is incorporated herein byreference, however, the present invention is not limited to use withthis particular dispenser. Parts of a dispenser described in applicationSer. No. 07/801,243 which are relevant to an understanding of thepresent invention are illustrated in FIG. 2 and will now be describedbriefly to facilitate understanding of the cartridge.

The dispenser-vial includes a nozzle 2, wings 3, a bellows portion 4,wings 6 and a rear vial section 8 containing a storage supply of liquidmedicament. The dispenser is compressible in the longitudinal directionbetween its posterior wall 10 and the anterior nozzle 2. For thispurpose, the bellows portion 4 is constructed of a soft flexible plasticmaterial such as the thermoplastic resin sold under the name Kraton fromthe Shell Company. Resiliency of the dispenser can be provided by thespring quality of the accordion bellows made of Kraton. Kraton has anexcellent memory and can be an excellent spring. Alternatively,resiliency may also be provided by a longitudinally disposed spring (notillustrated) which urges the dispenser to expand upon compression.

The dispenser includes a drop cavity therein (not illustrated) whichholds a predetermined volume of fluid to be emitted in the form of adrop. Compression of the dispenser in its longitudinal direction createsa drop in pressure in the drop cavity to fill or “load” the drop cavitywith liquid where it is stored until it is emitted as a drop from theslit 12 (see FIG. 4) in nozzle 2. This compressed state will be referredto herein as the loaded state. Expansion of the dispenser from theloaded state (caused by the spring urges the fluid in the drop cavityunder pressure toward the nozzle 2 from which it is emitted in the formof a drop. It can be seen that the force which is required to actuatethis type of dispenser must ordinarily be applied in the direction ofthe nozzle and hence the eye. With this background information about theoperation of the piston-like dispenser in mind, the cartridge of theinvention will now be described.

In order to best understand the operation of the cartridge of theinvention, the structure and operation of the kind of dispenser- vialwhich the cartridge of the invention is specifically designed to actuatewill now be described in detail with reference to FIGS. 5 and 6.Thedispenser 110 includes an outer body 112, an inner body 114 fittedwithin the outer body 112, and a piston body 116 coupled to the outerbody 112. The outer body 112 and inner body 114 define a nozzle 120 forreleasing drops into a user's eye upon movement of the piston body 116relative to the outer body 112, as indicated by the arrows in FIGS. 5and 6. The nozzle 120 is the same as the nozzle 20.

The outer body 112 defines an outer nozzle portion 122 which receives aninner nozzle portion 124 of the inner body 114. The interface of theouter nozzle portion 122 and the inner nozzle portion 124 defines a seam125 which is normally closed (i.e., the inner and outer nozzle portionsare abutting one another as shown in the drawings), but can be opened bythe flow of medicament of sufficient pressure into the seam to releasethe medicament through the nozzle 120. As with the nozzle 20 describedabove, the outer body 112 is preferably molded from a relativelyflexible plastic material in comparison to the inner body 114. Thus, theouter nozzle portion 122 can be flexed relative to the inner nozzleportion 124 to open the seam 125 to release the medicament through thenozzle 120.

The outer body 112 includes an annular flange 126 which fits within acorresponding recess in the inner body 114, as shown in FIGS. 5 and 6.The inner body 114, on the other hand, includes an annular lip 128 whichretains the inner body 114 within the outer body 112. The inner body 114is therefore pressed into the outer body 112 and coupled to the outerbody by guiding the flange 126 into the corresponding recess andsnapping the outer body 114 within the lip 128 of the inner body.

The outer body 112 further includes a bellows 130 and a flange 132coupled to the piston body 116. A medicament chamber 133 is thus definedwithin the outer body 112 and within the piston body 116, as shown inFIGS. 5 and 6. The piston body 116 includes an aperture 135 to permitthe medicament within the chamber 133 to flow between the interior ofthe outer body 112 and the interior of the piston body 116. The pistonbody 116 includes a lobe 134 which is snapped into a correspondingrecess in the flange 132 to couple the piston body to the outer body112, as shown in FIGS. 5 and 6. As will be recognized by those skilledin the art, however, the outer body 112 and piston body 116 can equallybe molded as an integral body to further prevent any leaks within theapparatus due to changes in the ambient pressure or temperature, forexample.

The outer end of the piston body 116 is sealed in a manner known tothose skilled in the art to retain the medicament within the medicamentchamber 133. The other end of the piston body 116 can also be coupled toanother container, for example, for pre-packaging the medicament in amanner known to those skilled in the art. The bellows 130 is adapted toflex inwardly to permit the piston body 116 to move relative to the outebody 112 to release medicament stored within the medicament chamber 133through the nozzle 120.

The inner body 114 includes a first substantially cylindrical wall 136essentially defining a hollow shaft projecting in the axial direction ofthe dispenser 110 and surrounding a rod member 118, as shown in FIGS. 5and 6. A first channel 138 is defined between the rod member 118 and thefirst cylindrical wall 136, and a second channel 140 extends between thefirst channel 138 and the seam 125.

The piston body 116 includes a bushing 142 which receives the firstcylindrical wall 136, and thus guides the piston body 116 as it is movedalong the first cylindrical wall. As shown in FIGS. 5 and 6, theinterior surface of the bushing 142 defines a generally concave profilefor engaging the cylindrical wall 136 in a fluid-tight manner, and thussubstantially prevents the flow of medicament between the bushing 142and the cylindrical wall 136 upon moving the piston body 116 to releasemedicament.

The piston body 116 further includes a second cylindrical wall 144 whichis substantially concentric with the first cylindrical wall 136, anddefines at least two slots 146 coupling the interior of the secondcylindrical wall 144 in fluid communication with the medicament chamber133. As shown in FIGS. 5 and 6, the rod member 118 is coupled to thefirst cylindrical wall 136 by means of a lobe 148 which snaps into acorresponding recess in the first cylindrical wall. A flange 150 on theend of the rod member 118 rests against the top surfaces of the firstcylindrical wall 136 and the second cylindrical wall 144 to prevent thepiston body 116 from being moved any further away from the nozzle 120.

As shown in FIGS. 5 and 6, a flange member 152 is coupled to the end ofthe first cylindrical wall 136 and tapers outwardly so that its free endengages the interior surface of the second cylindrical wall 144. Thesecond cylindrical wall 144 and the flange member 152 thus define a dropcavity 154 for holding medicament for release into the eye. The dropcavity 154 is preferably dimensioned to cause less than about 30microliters of medicament to be released each time the dispenser 110 isactuated. For many medicaments, the drop cavity 154 is preferablydimensioned to release approximately 15 to 20 microliters of medicamenteach time the apparatus is actuated. This volume of medicament is onlyexemplary, however, and can be changed as desired by changing the volumeof the drop cavity 154, for example. The free end of the flange member152 is dimensioned so that it engages the interior surface of the secondcylindrical wall 144 in order to substantially prevent the flow ofmedicament between the second cylindrical wall 144 and the flange member152 upon movement of the piston body 116, as indicated by the arrows inFIGS. 5 and 6. The first cylindrical wall 136 defines an aperture 156extending between the first channel 138 and the drop cavity 154 topermit the flow of medicament from the drop cavity 154, through thefirst channel 138 and second channel 140, for release through the nozzle120 into the eye.

In the operation of the dispenser 110, the apparatus is normallyoriented in the position shown in FIG. 3 (i.e., the bellows 130 is in arelaxed state). The dispenser 110 is actuated to release medicamentthrough the nozzle 120 by depressing the piston body 116 toward theouter body 112, as shown in FIGS. 6. As a result, the bellows 130 isdepressed inwardly and the bushing 142 is moved down toward the nozzle120, causing a suction to develop within the drop cavity 154, the firstchannel 138 and the second channel 140. The suction facilitates the flowof medicament from the medicament chamber 133 through the slots 146 tofill the drop cavity 154 and the first and second channels 138 and 140.Once the piston body 116 reaches the end of its downward stroke, asshown in FIG. 6 , the piston body is released, thus permitting the coilspring 158 to drive the piston body 116 in the opposite direction awayfrom the nozzle 120.

As a result, the bushing 142 slides back along the first cylindricalwall 136 toward the flange member 152. Then, at about the point that thebottom of each slot 146 passes over the end of the flange portion 152,the medicament in the drop cavity 154 is forced by the bushing 142through the aperture 156 and into the first channel 138. The pressurizedmedicament flows through the second channel 140, into the seam 125, andout through the tip of the nozzle 120 for release into the eye. Thepressure caused by the force of the coil spring 158 driving the bushing142 is sufficient to cause the medicament to open the seam 125 so thatthe complete dose of medicament is released into the eye. Then, once themedicament is released, the seam 125 returns to its normally closedposition to substantially prevent any medicament that is exposed to airfrom flowing back into the apparatus. The dispenser 110 is then ready tobe actuated again to release another dose of medicament.

One advantage of this type of dispenser is that a substantiallypredetermined volume of medicament can be released into an eye each timethe dispenser is actuated. The predetermined volume released can becontrolled by controlling the volume of the drop cavity, for example.Another advantage of the dispenser of the present invention is that oncea dose of medicament is released, the seam of the nozzle closes, andthus substantially prevents medicament which has been exposed to air orforeign particles from passing through the nozzle and into theapparatus, which can, in some instances, contaminate the remainder ofthe medicament in the apparatus. This advantage is particularlyimportant when storing multiple-dose quantities of preservative-freeformulations of medicament or other substances within the apparatus.

Another advantage of the dispenser 110 is that the pumping mechanism,which includes the first cylindrical wall 136 and the actuating member142, is contained entirely within the medicament chamber 133, and thusfurther prevents any contamination of the remaining medicament withinthe apparatus when actuating the pumping mechanism. Another advantage ofthe dispenser 110 is that the medicament is dispensed upon the releaseof the piston body 116. In this way, the same quantity of medicament isreleased each time the apparatus is actuated, because it is the force ofthe coil spring 158 which causes the medicament to be dispensed from theapparatus. Thus, the dispenser 110 can be used to reliably dispensemedicament, regardless of whether a user's hand shakes, or if there arevariations in the speed of the downward stroke of the piston body 116.

The dispenser 110 may be housed in and actuated by the cartridge of theinvention which will now be described. The outer body 112 is seatedagainst a surface of the cartridge which is depicted by phantom lines inFIGS. 5 and 6, in order to maintain the outer body 112 in a stationaryposition. A coil spring 158 is preferably seated between the surface ofthe cartridge and an annular lip 160 on the flange 132. The coil spring158 is provided to drive the piston body 116 to return to its normalposition for dispensing medicament.

Referring to FIGS. 1 and 2, the cartridge which is generally indicatedat 14 includes a cylindrical housing 16 which slidably receives an innercylindrical member 18 through a back open end 20. Preferably, the backof the housing 16 has a wall 17 to fit around the portion of thecylinder 18 which projects outside of the housing. The wall 17 will abuta recessed portion 19 of the inner cylinder 18 to close off the housingto external vapor and moisture.

The front of the housing 1 is substantially closed by an anterior wall22 which has an aperture 24 centrally located therein allowing for theprojection of the nozzle 2 of the dispenser. Preferably, the front ofthe housing 16 has a smooth arcuate external surface 23 (see FIG. 1) inthe event that the cartridge accidentally makes contact with the face.When the dispenser is mounted in the cartridge it sits between theanterior wall 22 and the member 18 as illustrated. The inner surface ofhousing 16 includes an annular rim 26. Anterior wall 22 and annular rim26 wedge wing 3 of the dispenser therebetween to prevent displacement ofthe dispenser within housing 14.

The lower anterior section of housing 16 includes a forwardly projectingfinger 28 which extends from the housing 16 beyond the tip of nozzle 2.The finger is upwardly curved to define a smooth surface 30 for engagingthe lower eyelid. The finger is preferably coated with a material suchas Kraton.

The inner cylinder 18 has a front section 31 which is attached to thevial section 8 of the dispenser. If desired, the inner cylinder 18 maybe formed integrally with the storage section 8. The front upper sectionof the inner cylinder 18 has an outwardly and rearwardly projectingextension 32 which engages and presses against the inner surface ofhousing 16. The extension 32 is flexible in the direction transverse tothe longitudinal axis of the cartridge 14. The tip 34 of the extension32 has a surface which is positioned and adapted to engage a notch 36formed on the inside surface of housing 16. The notch 36 is inclined andsmooth on its posterior side 38 but is cornered with the housing wall onits anterior side 40. The inner cylinder 18 and extension 32 arepositioned in the housing such that the tip 34 of the extension isposterior to the notch 36 when the dispenser is in the non-loadedposition.

The cartridge 14 includes a trigger 42. The trigger 42 may be slidablypositioned in an opening of an upper housing 43 (see FIG. 1) so as to becapable of inward movement toward the central longitudinal axis of thecartridge. Alternatively, the trigger 42 may be integrally formed withthe housing 16 so that it pivots about a thin-walled living hingesection 44 (see FIG. 2). The inner surface of the trigger is formed witha projecting heel 46 whose function will become apparent from thefollowing description of the operation of the cartridge. As illustratedin FIG. 2, preferably the trigger 42 and the point of attachment of thefinger 28 to the housing 16 are disposed on opposite upper and lowersides of the housing, respectively, so that they are disposed along thehousing 180° apart.

Before positioning the cartridge 14 over the eye, the dispenser-vial inthe cartridge is first loaded by pushing the inner cylinder 18 inwardthereby compressing the bellows 4 of the dispenser. As the innercylinder 18 is pushed inward the extension 32 is forced to flex as itslides over notch 36. The tip 34 of extension 32 is able to smoothlyslide over the inclined surface 38 of notch 36. Once the tip 34 haspassed over the notch 36 the extension 32 will snap back into engagementwith the inner surface of housing 16. At this point the dispenser willbe in its loaded state as previously defined. In addition, the cartridge14 is in a locked position because the tip 34 of extension 32 will beunable to move over the cornered surface 40 of notch 36. The cartridge14 is now ready for positioning over the eye.

As discussed above, a drop of medicament is ideally deposited in theconjunctival cul de sac of the lower eyelid for maximum effectiveness.For this purpose, the engaging surface 30 of finger 28 is gently pressedon the lower eyelid. The cartridge is then moved downward slightly toexpose the cul de sac and the cartridge is positioned so that the nozzle2 will be directed toward the cul de sac. At this point the user woulddepress the trigger 42.

Referring to FIG. 3, when the trigger 42 is depressed the heel 46 willforce the extension 32 downward and the tip 34 will eventually clear theface 40 of notch 36. The spring in the dispenser will force thedispenser and the inner cylinder 18 to expand back to the non-loadedposition and at this time a drop of medicament will be released from theslit 12 of nozzle 2 into the eye as discussed above.

It should be appreciated that one advantage of the cartridge of theinvention is that the motion which is used to depress the trigger andthereby release a drop is in the same direction as the motion used tolower the eyelid and expose the cul de sac. Therefore, more accuratedelivery of the drop is possible. Furthermore, an area of lowsensitivity and low tear turn over is specifically targeted by thecartridge which prevents tearing and blinking reflex for betterefficacy.

In addition, there is no danger of poking the eyeball with the nozzle 2since the motion to depress the trigger is not in the direction of theeye and since the finger 28 extends beyond the nozzle. Moreover, whenthe trigger is depressed the return mechanism of the vial projects theinner cylinder in the direction away from the eye. The cartridge isparticularly useful for arthritic patients because the trigger mechanismallows for easy release of a drop.

In the foregoing specification, the invention has been described withreference to specific exemplary embodiments thereof. It will, however,be evident that various modifications and changes may be made thereuntowithout departing from the broader spirit and scope of the invention asset forth in the appended claims. The specification and drawings areaccordingly to be regarded in an illustrative rather than a restrictivesense.

What is claimed is:
 1. A cartridge for use with a dispenser for applyingmedicament to an eye comprising: a housing having an anterior wall withan aperture therein, the housing having an open back end; alongitudinally slidable member contained within, said member having aflexible outwardly projecting extension which has a tip engaging aninner surface of the housing; a notch disposed on the inner surface ofthe housing having an anterior face and a posterior face which areangled to the housing and which cooperate with the extension tip suchthat the extension tip can be forced over the posterior face uponsliding the slidable member toward the anterior wall to a lockedposition where the tip engages the anterior face of the notch, but thetip cannot be forced over the anterior face upon sliding the membertoward the back end of the housing from the locked position; and atrigger in the housing having an inner surface for engaging the flexibleextension, said trigger being movable to a position where its innersurface forces the flexible extension tip in its locked position in adirection towards the slidable member and away from the inner surface ofthe housing so that the tip is free to move past the notch upon slidingof the slidable member away from the anterior wall.
 2. The cartridgeaccording to claim 1 wherein the housing is cylindrical and wherein thefinger is attached along the housing at a point which is about 180° fromthe location of the trigger.
 3. The cartridge according to claim 1wherein the finger has a surface of a soft thermoplastic material. 4.The cartridge according to claim 1 wherein the inner surface of thetrigger has a projecting heel for engaging the flexible extension tip.5. The cartridge according to claim 1 wherein the posterior face of thenotch is a smooth inclined surface and wherein the anterior face of thenotch is a flat surface which is normal to the inner surface of thehousing.
 6. The cartridge according to claim 1 further comprising afinger for engaging an eyelid, the finger projecting from an outersurface of the housing and extending out to a point anterior to theanterior wall.
 7. A cartridge in combination with a dispenser forapplying medicament to an eye, the dispenser being of the type which isactuated to load a drop of medicament into a cavity therein bycompression in its longitudinal direction to a compressed position andwhich is actuated to emit said drop from a nozzle upon subsequentexpansion from said compressed position, the cartridge comprising: ahousing retaining the dispenser therein, the housing having an anteriorwall with an aperture therein receiving the nozzle of the dispenser andthe housing having an open back end; a telescoping member, containedwithin for compressing the dispenser in its longitudinal direction; ameans for locking the telescoping member in a position where thedispenser is in a compressed position; and a trigger means fordisengaging the means for locking to allow the dispenser to expand fromsaid compressed position.
 8. The cartridge according to claim 7 furthercomprising a finger for engaging an eyelid, the finger projecting fromthe housing in an anterior direction to a point anterior to the anteriorwall.
 9. A cartridge in combination with a dispenser for applyingmedicament to an eye, the dispenser comprising: a container holding avolume of fluid; a first dosage cavity forming member and a seconddosage cavity forming member, the second member being movable between: afirst position, in which the first member and the second member togetherdefine a cavity which is in fluid communication with the container; asecond position, in which the first member and the second membertogether define a cavity having a certain predetermined volume and inwhich the cavity is not in fluid communication with the container; and athird position in which the volume of the cavity is less than the volumeof the cavity in the second position and in which the cavity is not influid communication with the container; a means for biasing the seconddosage cavity forming member to the third position; and a nozzle whichis in fluid communication with the cavity, wherein a dosage of fluid inthe cavity is forced through the nozzle and out of the apparatus uponmovement of the second member from the first position or the secondposition to the third position under the action of the biasing means,and wherein the second member is selectively movable from the thirdposition back to the first position to draw fluid from the containerinto the cavity after each dosage of fluid is forced through the nozzleout of the apparatus, the cartridge comprising: a housing which housesthe dispenser, the housing having an opening which exposes the nozzle ofthe dispenser; a pushable member coupled to said housing and beingslidable relative to said housing and pushable against a compressibleportion of said dispenser, the pushable member being slidable between: afirst position wherein the second dosage cavity forming member is in itsfirst position; a second position wherein the second cavity formingmember of the dispenser is in its second position; and a third positionwherein the second cavity forming member of the dispenser is in itsthird position, said pushable member being selectively and releasablylockable with respect to the housing in either the first position or thesecond position so as to releasably lock the second dosage cavityforming member in a corresponding position; and a means for biasing saidpushable member and the second dosage cavity forming member toward thethird position, said biasing means forcing said pushable member to movefrom said first or second position to said third position when saidpushable member is unlocked relative to said housing in said first orsecond position.
 10. The combination according to claim 9 wherein themeans for biasing includes a spring.
 11. The combination according toclaim 9 wherein the means for biasing includes a bellows region in thecompressible portion of the dispenser.
 12. The combination according toclaim 10 wherein the spring is compressible between a portion of thedispenser and the housing.
 13. The combination according to claim 9wherein the means for biasing includes a spring which is biased againstone of the dosage cavity forming members of the dispenser.
 14. Acartridge in combination with a dispenser for applying medicament to aneye, the dispenser being of the type which is actuated to loadmedicament into a cavity therein by compression of the dispenser andwhich is actuated to force said medicament from the cavity and out of anozzle of the dispenser upon subsequent decompression of the dispenser,said cartridge comprising: a housing retaining the dispenser therein; apushable member coupled to said housing for compressing the dispenser,said pushable member being slidable relative to said housing between afirst position in which the dispenser is compressed and a secondposition in which the dispenser is decompressed, said pushable memberbeing selectively lockable and unlockable in said first position; and ameans for biasing said pushable member toward the second position, saidbiasing means forcing said pushable member to move from said firstposition to said second position when said pushable member is unlockedin said first position.
 15. A method of applying a dose of medicamentusing a cartridge in combination with a dispenser, said dispenser beingof the type which is actuated to load medicament from a reservoirtherein into a medicament-holding cavity of said medicament from saidmedicament-holding cavity upon subsequent decompression of saiddispenser, said cartridge being of the type which has a movablecompressing member for compressing said dispenser and a biasing meansoperatively coupled to said compressing member, said method comprising:compressing said dispenser by moving said compressing member from afirst position to a second position, whereby said medicament is loadedinto said medicament-holding cavity; locking said compressing member insaid second position relative to said cartridge; unlocking saiddispenser in said second position relative to said cartridge; andbiasing said compressing member back toward said first position, wherebysaid dispenser is restored to a decompressed state and said medicamentis ejected from said medicament-holding cavity.